Removing Failed Hammertoe Implants Following Nonunion
All the above findings were more pronounced on the left foot. The affected toes also demonstrated no deviation in skin temperature, hydration or hair growth in comparison with the same areas on the other, asymptomatic post-surgical toes.
The biomechanical evaluation demonstrated bilateral ankle equinus as well as flexible flatfoot. The remainder of the physical examination was unremarkable.
We compared standard weightbearing radiographs of both feet to those taken in the initial, immediate postoperative period. Repeat imaging revealed continued soft tissue edema of bilateral fourth digits in addition to interval failure of the implant with evidence of nonunion at the PIPJ arthrodesis site of the third and fourth digits on the right foot and four on the left foot. No other complicating process or abnormality was visible. There was no evidence of periosteal reaction, adjacent cortical disruption, osteophytic proliferation or cystic formation within the affected joints.
What You Should Know About Implant Removal
Based on the progressive clinical symptomatology and imaging findings, we proceeded to the operating room for surgical inspection, attempted removal of failed implants and attempted bone biopsy. This was an effort to make an accurate diagnosis and to attempt to alleviate the initial complaint of pain, which we believed to be directly related to the failed internal fixation device and suspected nonunion.
In the operating room, the surgeon made a linear longitudinal incision over the dorsal aspect of the PIPJ using prior skin incision sites. We noted extensive fibrous tissue surrounding the attempted PIPJ fusion site. Upon entry and exposure into the affected joints, no osseous union was visible. Upon further inspection, we noted that the retained metallic implants in the fourth toes were fractured at the lateral aspect of the distal arm with associated multiplanar mobility at the PIPJ. In the left foot, there was more significant sagittal and frontal plane rotation.
The implants were relatively rigid and exhibited moderate resistance upon removal from the proximal and middle phalynx components. We fully removed the right device but the left was embedded within the middle phalynx. We could not visualize the lateral most aspect and remove it without aggressive osseous resection. We decided intraoperatively to allow this remnant to remain as complete removal might have resulted in further, unnecessary destruction as no evidence of the metallic implant was directly visible nor was impingement visible at the PIPJ upon movement.
The remaining osseous tissue was normal in appearance and texture. We sent a specimen for pathologic examination to ensure that no evidence of osteomyelitis was present. The surgeon rasped the hypertrophied osseous prominence smooth. After copious irrigation, we placed bone putty within the voids from implant removal. Layered closure allowed for accurate approximation of the extensor tendon, subcutaneous tissues and skin with toes maintaining rectus alignment.
The gross pathological examination of the specimens was “heavily mineralized, necrotic lamellar bone” with diffuse marrow fibrosis. There was no evidence of osteomyelitis. We feel this is likely due to nonunion resulting in micromotion and continual rotational stressors that ultimately led to device failure and further inflammation and pain.